Operating Leases (Details Textual) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Operating Leases (Textual) [Abstract]
Total term of lease facility	30 years
Initial term of lease facilities	15 years
Number of additional extensions on lease facility	3
Extended period of lease under option	5 years
Future, non-cancelable sublease payments	$ 1.3
Total rent expense under all operating leases	$ 51.8	$ 53.8	$ 51.5